Introduction Haemophilia A or B patients with inhibitors have been treated with FVIIa‐containing bypassing agents for over 20 years. However, due to uncertainty regarding dose response and thrombotic risk, the use of a gradual, titrated, minimal dosing strategy remains prevalent, potentially hampering early haemostasis. Aim Evaluate the dose‐dependent efficacy, safety and immunogenicity of activated eptacog beta (rhFVIIa), a new recombinant inhibitor bypassing agent for the treatment of bleeding episodes (BEs). Methods A Phase 3, randomized, cross‐over study of initial dose regimens (IDRs) in 27 bleeding congenital haemophilia A or B subjects with inhibitors was conducted to evaluate on‐demand treatment of mild/moderate BEs. Intravenous 75 μg/kg or 225 μg/kg initial doses with 75 μg/kg subsequent doses by schedule were administered until clinical response. Results The primary endpoint was sustained clinical response within 12 hours, determined by a composite of objective and pain measures. In the 75 μg/kg IDR, 84.9% (95% CI; 74.0%, 95.7%) of mild/moderate BEs at 12 hours were successfully treated compared to 93.2% (95% CI; 88.1%, 98.3%) treated in the 225 μg/kg IDR. Efficacy between the IDRs was statistically different (P<.020) in mild/moderate bleeding episodes. Both IDRs were well tolerated with no detectable immunogenic or thrombotic responses to rhFVIIa or host cell proteins. Conclusion The dose‐dependent efficacy seen in this study supports individualizing the initial dose of eptacog beta to optimize clinical response. By reducing uncertainty, the PERSEPT 1 results should increase the adoption of early haemostasis as a treatment goal for clinicians who treat haemorrhage in the inhibitor population.

Introduction Varying initial doses of activated eptacog beta (recombinant human FVIIa, rhFVIIa) may provide therapeutic options when treating bleeding in patients with congenital haemophilia who have developed inhibitory antibodies to factor VIII (FVIII) or factor IX (FIX). This study evaluated escalated doses of a new rhFVIIa product as a prelude to selecting the doses for clinical efficacy evaluation in haemophilia patients. Aim To assess the safety, pharmacokinetics, and laboratory pharmacodynamics of 3 doses of rhFVIIa in non‐bleeding patients with congenital haemophilia A or B with or without inhibitors. Methods Adult male patients (18‐75 years old) with congenital haemophilia A or B (with or without inhibitors) received infusions of rhFVIIa at doses of 25, 75 or 225 μg/kg body weight. Ten patients were treated at each dose level, and each patient received 2 different dose levels. Descriptive methods were used to analyse the data. Results Administration of rhFVIIa at all doses was well tolerated. Pharmacokinetic analyses showed that peak FVIIa plasma levels (Cmax) were approximately proportional to dose and correlated well with peak thrombin generation. Total AUC0‐inf also was approximately dose proportional. Clot formation and duration correlated with FVIIa activity. Repeat doses did not produce an immunological response. Conclusion In the first dose‐escalation study of rhFVIIa to support product registration, eptacog beta at doses of 25, 75, and 225 μg/kg was pharmacodynamically active and well tolerated in non‐bleeding patients with congenital haemophilia A or B.